July 6, 2023 – A new government estimate says at least 45% of the tap water in the U.S. contains PFAS, which are substances also known as “forever chemicals.”
It’s the first time that scientists have estimated how common PFAS are in drinking water at a national level. PFAS (short for perfluoroalkyl and polyfluoroalkyl substances) are synthetic chemicals that contaminate the environment from a variety of products. They can be present in water, food, the ground, and the air; and long-term exposure results in the chemicals building up in the body over time, which can be harmful, according to the U.S. Environmental Protection Agency.
This latest study was done by the U.S. Geological Survey (USGS) and published last month in the journal Environment International. The USGS analyzed data from 269 private wells and 447 public water supplies, and then created a national estimate from the results. (The USGS is a government agency that makes maps and analyzes national natural resource data.)
“USGS scientists tested water collected directly from people’s kitchen sinks across the nation, providing the most comprehensive study to date on PFAS in tap water from both private wells and public supplies,” study author and USGS research hydrologist Kelly Smalling, MSPH, said in a statement. “The study estimates that at least one type of PFAS – of those that were monitored – could be present in nearly half of the tap water in the U.S. Furthermore, PFAS concentrations were similar between public supplies and private wells.”
The water sampled for the study spanned the country and U.S. territories, including Alaska, Hawaii, Puerto Rico, and the U.S. Virgin Islands. Researchers classified sample sites as low, medium, or high human-impact areas. High human-impact areas include urban areas and waste sites, where the researchers estimate that just 25% of tap water may be free of PFAS. In rural areas, 75% of tap water is estimated to be free of PFAS, they wrote.
The regions of the country where PFAS-contaminated water was most often observed included the Great Plains, Great Lakes, Eastern Seaboard, and Central/Southern California regions.
PFAS can be filtered out of water, according to the EPA, which is considering regulating drinking water for the presence of some specific PFAS.